up a creek
Also, up shit creek; up the creek (without a paddle). In trouble, in a serious predicament, as in If the check doesn't arrive today I'm up a creek, or The car wouldn't start, so I was up the creek without a paddle. This slangy idiom conjures up the image of a stranded canoeist with no way of moving (paddling) the canoe. President Harry S. Truman used the first term in a letter in 1918. The first variant is considered vulgar.